The topic of self-interest raises large and intractable philosophical questions–most obviously, the question “In what does self-interest consist?” The concept, as opposed to the content of self-interest, however, seems clear enough. Self-interest is interest in one's own good. To act self-interestedly is to act on the motive of advancing one's own good. Whether what one does actually is in one's self-interest depends on whether it actually does advance, or at least, minimize the decline of, one's own good. Though it may be difficult to tell whether a person is motivated by self-interest in a particular instance, and difficult also to determine whether a given act or decision really is in one's self-interest, the meaning of the claims in question seems unproblematic. My main concern in this essay is to make a point about the content of self-interest. Specifically I shall put forward the view that meaningfulness, in a sense I shall elaborate, is an important element of a good life. It follows, then, that it is part of an enlightened self-interest that one wants to secure meaning in one's life, or, at any rate, to allow and promote meaningful activity within it. Accepting this substantial conception of self-interest, however, carries with it a curious consequence: the concept of self-interest which formerly seemed so clear begins to grow fuzzy. Fortunately, it comes to seem less important as well. In Reasons and Persons, Derek Parfit distinguishes three sorts of theories about self-interest–hedonistic theories, preference theories, and what he calls “objective-list theories." Hedonistic theories hold that one's good is a matter of the felt quality of one's experiences